Australia are waiting to discover the extent of a knee injury sustained by Josh Mansour in training on Wednesday.
The Penrith Panthers wing was helped from the field after reportedly colliding with team-mate Josh Dugan, with concerns he could have suffered a serious injury.
Mansour scored two tries as the Kangaroos hammered Scotland 54-12 in the first game of the Four Nations last Friday, but his participation in the remainder of the tournament now appears to be doubt.
The 26-year-old, who suffered a medial ligament injury two years ago, was taken for a scan and must now wait for the outcome.
Mansour was in line to start for Mal Meninga's side against defending champions New Zealand at the Ricoh Arena in Coventry on Saturday following his impressive display against Scotland.
Josh Mansour impressed in Australia's first game of the Four Nations, but there are concerns his tournament may now be over.